Cells and Proteins

Question 1

Describe an organisms ‘genome’

Answer 1

complete set of DNA, containing both the protein coding regions and the non protein coding regions of DNA

Question 2

what’s a proteome?

Answer 2

entire set of proteins that can be expressed from the genome

Question 3

why is the proteome much bigger than the genome?

Answer 3

alternative RNA splicing

post translational modification

Question 4

what is the monomer of a protein

Answer 4

amino acid

Question 5

what happens to an amino acid when in aqueous solution?

Answer 5

nh2 gains a hydrogen forming nh3+

cooh loses a hydrogen forming coo-

Question 6

what are the four classes of amino acids?

Answer 6

acidic
basic
polar
hydrophobic

(phab)

Question 7

give an example of an acidic amino acid

Answer 7

aspartic acid

Question 8

give an example of a polar functional group

Answer 8

oh

Question 9

give an example of a basic amino acid

Answer 9

lysine

Question 10

give an example of a hydrophobic amino acid

Answer 10

alanine

Question 11

is acidic amino acid class positively or negatively charged

Answer 11

negatively charged

Question 12

what kind of bonds can polar r groups form with molecules such as water

Answer 12

hydrogen bonds

Question 13

why do hydrophobic r groups not readily mix with water

Answer 13

they carry no charge and so don’t form hydrogen bonds with water

Question 14

what type of reaction is it that occurs when amino acids are joined together during translation

Answer 14

condensation, water is produced

Question 15

what is the bond called that links amino acids

Answer 15

peptide bond

Question 16

what is present at the n terminus of a polypeptide chain

Answer 16

nh2

Question 17

where can a cooh be found in a polypeptide

Answer 17

at a c terminus

Question 18

describe a primary structure of a protein

Answer 18

the order in which the amino acids are synthesised from an n terminus to a c terminus

Question 19

what is the secondary structure mainly stabilized by (type of bond)

Answer 19

hydrogen bonds

Question 20

where do hydrogen bonds exist between on the polypeptide chain

Answer 20

different peptide bonds

between the nh and c=o of another peptide bond

Question 21

what are the two types of secondary structure

Answer 21

alpha helix

beta sheet

Question 22

describe an alpha helix

Answer 22

spiral of polypeptide chain

r groups sticking outwards

Question 23

where do the r groups sit in a beta sheet

Answer 23

above and below the main chain

Question 24

what are the two types of beta sheets you can get

Answer 24

parallel and antiparallel

Question 25

what is a turn in a polypeptide chain

Answer 25

where the chain folds back on itself

Question 26

what is the function of interactions between R groups in tertiary structure

Answer 26

stabilise regions of secondary structure

Question 27

name three possible interactions between R groups

Answer 27

hydrophobic
Ionic bonds
Van Der Waals
disulphide bridges